NoncentralBetaDistribution[\[Alpha], \[Beta], \[Delta]] represents a noncentral beta distribution with shape parameters \[Alpha], \[Beta] and noncentrality parameter \[Delta].
NoncentralChiSquareDistribution[\[Nu], \[Lambda]] represents a noncentral \[Chi]^2 distribution with \[Nu] degrees of freedom and noncentrality parameter \[Lambda].
NoncentralFRatioDistribution[n, m, \[Lambda]] represents a noncentral F-ratio distribution with n numerator degrees of freedom, m denominator degrees of freedom, and ...
NoncentralStudentTDistribution[\[Nu], \[Delta]] represents a noncentral Student t distribution with \[Nu] degrees of freedom and noncentrality parameter \[Delta].
ParallelCombine[f, h[e_1, e_2, ...], comb] evaluates f[h[e_1, e_2, ...]] in parallel by distributing parts of the computation to all parallel kernels and combining the ...
PascalDistribution[n, p] represents a Pascal distribution with parameters n and p.
PolyaAeppliDistribution[\[Theta], p] represents a Polya\[Dash]Aeppli distribution with shape parameters \[Theta] and p.
Polygon
(Built-in Mathematica Symbol) Polygon[{pt_1, pt_2, ...}] is a graphics primitive that represents a filled polygon. Polygon[{{pt_11, pt_12, ...}, {pt_21, ...}, ...}] represents a collection of polygons.
RayleighDistribution[\[Sigma]] represents the Rayleigh distribution with scale parameter \[Sigma].
SinghMaddalaDistribution[q, a, b] represents the Singh\[Dash]Maddala distribution with shape parameters q and a and scale parameter b.